Toxicology of tramadol following chronic exposure based on metabolomics of the cerebrum in mice

Disease diagnosis and application analysis of molecularly imprinted polymers (MIPs) in saliva detection

Saliva has significantly evolved as a diagnostic fluid in recent years, giving a non-invasive alternative to blood analysis. A high protein concentration in saliva is delivered directly from the bloodstream, making it a "human mirror" that reflects the body's physiological state. It plays an essential role in detecting diseases in biomedical and fitness monitoring. Molecularly imprinted polymers (MIPs) are biomimetic materials with custom-designed synthetic recognition sites that imitate biological counterparts renowned for sensitive analyte detection. This paper reviews the progress made in research about MIP biosensors for detecting saliva biomarkers. Specifically, we investigate the link between saliva biomarkers and various diseases, providing detailed insights into the corresponding biosensors. Furthermore, we discuss the principles of molecular imprinting for disease diagnostics and application analysis, including recent advances in integrated MIP-sensor technologies for high-affinity analyte detection in saliva. Notably, these biosensors exhibit high discrimination, allowing for the detection of saliva biomarkers linked explicitly to chronic stress disorders, diabetes, cancer, bacterial or viral-induced illnesses, and exposure to illicit toxic substances or tobacco smoke. Our findings indicate that MIP-based biosensors match and perhaps surpass their counterparts featuring integrated natural antibodies in terms of stability, signal-to-noise ratios, and detection limits. Additionally, we highlight the design of MIP coatings, strategies for synthesizing polymers, and the integration of advanced biodevices. These tailored biodevices, designed to assess various salivary biomarkers, are emerging as promising screening or diagnostic tools for real-time monitoring and self-health management, improving quality of life.

The toxic profile of tramadol combined with nicotine on the liver and testicles: evidence from endoplasmic reticulum stress

BACKGROUND

Tramadol is one of the most commonly abused substances in the Middle East. Furthermore, smoking is extremely common among the population.

METHODS

An experimental study was performed on Sprague-Dawley rats to explore the effects of both nicotine and tramadol on the liver and testes. The tramadol was administered at 10 and 20 mg/kg, respectively, while the nicotine was administered at 125 mg/kg. Histological examination and androgen receptor ELISA assay showed mild effects on the liver and proofed safety on the testis. Western blot analysis of BIP (immunoglobulin heavy-chain binding protein) and CHOP (CCAAT-enhancer-binding protein homologous protein) revealed that fewer problems were induced by adding nicotine to tramadol. Autophagy marker LCIII and apoptosis marker caspase-8 showed similar effects to CHOP and BIP on liver samples. The real-time PCR of BIP expression showed similar but not identical results.

CONCLUSIONS

The results showed mild endoplasmic reticulum stress, autophagy, and apoptosis in the liver samples. Histological examination revealed stable spermatogenesis with average androgen receptor blood levels in the different groups.

Nomilin and its analogue obacunone alleviate NASH and hepatic fibrosis in mice via enhancing antioxidant and anti-inflammation capacity

Nonalcoholic steatohepatitis (NASH) and hepatic fibrosis are leading causes of cirrhosis with rising morbidity and mortality worldwide. Currently, there is no appropriate treatment for NASH and hepatic fibrosis. Many studies have shown that oxidative stress is a main factor inducing NASH. Nomilin (NML) and obacunone (OBA) are limonoid compounds naturally occurring in citrus fruits with various biological properties. However, whether OBA and NML have beneficial effects on NASH remains unclear. Here, we demonstrated that OBA and NML inhibited hepatic tissue necrosis, inflammatory infiltration and liver fibrosis progression in methionine and choline-deficient (MCD) diet, carbon tetrachloride (CCl4 )-treated and bile duct ligation (BDL) NASH and hepatic fibrosis mouse models. Mechanistic studies showed that NML and OBA enhanced anti-oxidative effects, including reduction of malondialdehyde (MDA) level, increase of catalase (CAT) activity and the gene expression of glutathione S-transferases (GSTs) and Nrf2-keap1 signaling. Additional, NML and OBA inhibited the expression of inflammatory gene interleukin 6 (Il-6), and regulated the bile acid metabolism genes Cyp3a11, Cyp7a1, multidrug resistance-associated protein 3 (Mrp3). Overall, these findings indicate that NML and OBA may alleviate NASH and liver fibrosis in mice via enhancing antioxidant and anti-inflammation capacity. Our study proposed that NML and OBA may be potential strategies for NASH treatment.

Neuroprotective potential of trimetazidine against tramadol-induced neurotoxicity: role of PI3K/Akt/mTOR signaling pathways

Tramadol (TRA) causes neurotoxicity whereas trimetazidine (TMZ) is neuroprotective. The potential involvement of the PI3K/Akt/mTOR signaling pathway in the neuroprotection of TMZ against TRA-induced neurotoxicity was evaluated. Seventy male Wistar rats were divided into groups. Groups 1 and 2 received saline or TRA (50 mg/kg). Groups 3, 4, and 5 received TRA (50 mg/kg) and TMZ (40, 80, or 160 mg/kg) for 14 days. Group 6 received TMZ (160 mg/kg). Hippocampal neurodegenerative, mitochondrial quadruple complex enzymes, phosphatidylinositol-3-kinases (PI3Ks)/protein kinase B levels, oxidative stress, inflammatory, apoptosis, autophagy, and histopathology were evaluated. TMZ decreased anxiety and depressive-like behavior induced by TRA. TMZ in tramadol-treated animals inhibited lipid peroxidation, GSSG, TNF-α, and IL-1β while increasing GSH, SOD, GPx, GR, and mitochondrial quadruple complex enzymes in the hippocampus. TRA inhibited Glial fibrillary acidic protein expression and increased pyruvate dehydrogenase levels. TMZ reduced these changes. TRA decreased the level of JNK and increased Beclin-1 and Bax. TMZ decreased phosphorylated Bcl-2 while increasing the unphosphorylated form in tramadol-treated rats. TMZ activated phosphorylated PI3Ks, Akt, and mTOR proteins. TMZ inhibited tramadol-induced neurotoxicity by modulating the PI3K/Akt/mTOR signaling pathways and its downstream inflammatory, apoptosis, and autophagy-related cascades.

Impact of Opioids on Cellular Metabolism: Implications for Metabolic Pathways Involved in Cancer

Opioid utilization for pain management is prevalent among cancer patients. There is significant evidence describing the many effects of opioids on cancer development. Despite the pivotal role of metabolic reprogramming in facilitating cancer growth and metastasis, the specific impact of opioids on crucial oncogenic metabolic pathways remains inadequately investigated. This review provides an understanding of the current research on opioid-mediated changes to cellular metabolic pathways crucial for oncogenesis, including glycolysis, the tricarboxylic acid cycle, glutaminolysis, and oxidative phosphorylation (OXPHOS). The existing literature suggests that opioids affect energy production pathways via increasing intracellular glucose levels, increasing the production of lactic acid, and reducing ATP levels through impediment of OXPHOS. Opioids modulate pathways involved in redox balance which may allow cancer cells to overcome ROS-mediated apoptotic signaling. The majority of studies have been conducted in healthy tissue with a predominant focus on neuronal cells. To comprehensively understand the impact of opioids on metabolic pathways critical to cancer progression, research must extend beyond healthy tissue and encompass patient-derived cancer tissue, allowing for a better understanding in the context of the metabolic reprogramming already undergone by cancer cells. The current literature is limited by a lack of direct experimentation exploring opioid-induced changes to cancer metabolism as they relate to tumor growth and patient outcome.

Long-Term Effects of Developmental Exposure to Oxycodone on Gut Microbiota and Relationship to Adult Behaviors and Metabolism

Opioid drugs are commonly prescribed analgesic to pregnant women. Direct exposure to such drugs may slow gut motility, alter gut permeability, and affect the gut microbiome. While such drugs affect gut microbiome in infants, no study to date has determined whether developmental exposure to such drugs results in longstanding effects on gut microbiota and correspondingly on host responses. We hypothesized developmental exposure to oxycodone (OXY) leads to enduring effects on gut microbiota and such changes are associated with adult neurobehavioral and metabolic changes. Female mice were treated daily with 5 mg OXY/kg or saline solution (control [CTL]) for 2 weeks prior to breeding and then throughout gestation. Male and female offspring pups were weaned, tested with a battery of behavioral and metabolic tests, and fecal boli were collected adulthood (120 days of age). In females, relative abundance of Butyricimonas spp., Bacteroidetes, Anaeroplasma spp., TM7, Enterococcus spp., and Clostridia were greater in OXY versus CTL individuals. In males, relative abundance of Coriobacteriaceae, Roseburia spp., Sutterella spp., and Clostridia were elevated in OXY exposed individuals. Bacterial changes were also associated with predictive metabolite pathway alterations that also varied according to sex. In males and females, affected gut microbiota correlated with metabolic but not behavioral alterations. The findings suggest that developmental exposure to OXY leads to lasting effects on adult gut microbiota that might affect host metabolism, possibly through specific bacterial metabolites or other bacterial-derived products. Further work is needed to characterize how developmental exposure to OXY affects host responses through the gut microbiome.

IMPORTANCE This is the first work to show in a rodent model that in utero exposure to an opioid drug can lead to longstanding effects on the gut microbiota when examined at adulthood. Further, such bacterial changes are associated with metabolic host responses. Given the similarities between rodent and human microbiomes, it raises cause for concern that similar effects may become evident in children born to mothers taking oxycodone and other opioid drugs.

Graphene-Based Electrochemical Sensors for Psychoactive Drugs

Sensors developed from nanomaterials are increasingly used in a variety of fields, from simple wearable or medical sensors to be used at home to monitor health, to more complicated sensors being used by border customs or aviation industries. In recent times, nanoparticle-based sensors have begun to revolutionize drug-detection techniques, mainly due to their affordability, ease of use and portability, compared to conventional chromatography techniques. Thin graphene layers provide a significantly high surface to weight ratio compared to other nanomaterials, a characteristic that has led to the design of more sensitive and reliable sensors. The exceptional properties of graphene coupled with its potential to be tuned to target specific molecules have made graphene-based sensors one of the most popular and well-researched sensing materials of the past two decades with applications in environmental monitoring, medical diagnostics, and industries. Here, we present a review of developments in the applications of graphene-based sensors in sensing drugs such as cocaine, morphine, methamphetamine, ketamine, tramadol and so forth in the past decade. We compare graphene sensors with other sensors developed from ultrathin two-dimensional materials, such as transition-metal dichalcogenides, hexagonal boron nitrate, and MXenes, to measure drugs directly and indirectly, in various samples.

Endogenous opiates and behavior: 2020

This paper is the forty-third consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2020 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug abuse and alcohol (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).

Inflammatory Biomarkers in Addictive Disorders

Substance use disorders are a group of diseases that are associated with social, professional, and family impairment and that represent a high socio-economic impact on the health systems of countries around the world. These disorders present a very complex diagnosis and treatment regimen due to the lack of suitable biomarkers supporting the correct diagnosis and classification and the difficulty of selecting effective therapies. Over the last few years, several studies have pointed out that these addictive disorders are associated with systemic and central nervous system inflammation, which could play a relevant role in the onset and progression of these diseases. Therefore, identifying different immune system components as biomarkers of such addictive disorders could be a crucial step to promote appropriate diagnosis and treatment. Thus, this work aims to provide an overview of the immune system alterations that may be biomarkers of various addictive disorders.

Dietary soy, pork and chicken proteins induce distinct nitrogen metabolism in rat liver

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Dietary amino acid composition affected nitrogen metabolism in rat liver.

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Amino acid metabolizing enzymes were downregulated by meat protein diets.

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Ribosome assembly and protein synthesis were regulated by diet by mTOR pathway.

Diets have been shown to alter metabolism and gene expression. However, few data are available about changes in gene expression in liver after intake of different meat protein diets. This work aimed to explore the long-term effects of protein source on liver metabolic enzymes. Rats were fed protein diets for 90 days to study whether intake of chicken and pork protein diets promoted gene expression involved in hepatic metabolism. Liver proteome profiles were measured by iTRAQ labeling and LC–ESI–MS/MS. Chicken protein diet induced higher level of serum amino acids in rats than soy protein. Amino acid metabolizing enzymes were downregulated by pork and chicken protein diets compared with soy protein diet. Intake of meat protein diets downregulated enzymes involved in protein synthesis, disulfide bond formation, signal peptide addition, transport, localization, degradation and glycosylation modification, but upregulated enzymes involved in prolyl cis–trans isomerization for protein synthesis. Protein diets from different sources affected the amino acid supply, and further influenced ribosome assembly and protein synthesis through mTOR signaling pathway.

Effect of thermophilic bacterium HB27 manganese superoxide dismutase in a rat model of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS)

We investigated the therapeutic effects of superoxide dismutase (SOD) from thermophilic bacterium HB27 on chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) and its underlying mechanisms. A Sprague–Dawley rat model of CP/CPPS was prepared and then administered saline or Thermus thermophilic (Tt)-SOD intragastrically for 4 weeks. Prostate inflammation and fibrosis were analyzed by hematoxylin and eosin staining, and Masson staining. Alanine transaminase (ALT), aspartate transaminase (AST), serum creatinine (CR), and blood urea nitrogen (BUN) levels were assayed for all animals. Enzyme-linked immunosorbent assays (ELISA) were performed to analyze serum cytokine concentrations and tissue levels of malondialdehyde, nitric oxide, SOD, catalase, and glutathione peroxidase. Reactive oxygen species levels were detected using dichlorofluorescein diacetate. The messenger ribonucleic acid (mRNA) expression of tissue cytokines was analyzed by reverse transcription polymerase chain reaction (RT-PCR), and infiltrating inflammatory cells were examined using immunohistochemistry. Nuclear factor-κB (NF-κB) P65, P38, and inhibitor of nuclear factor-κBα (I-κBα) protein levels were determined using western blot. Tt-SOD significantly improved histopathological changes in CP/CPPS, reduced inflammatory cell infiltration and fibrosis, increased pain threshold, and reduced the prostate index. Tt-SOD treatment showed no significant effect on ALT, AST, CR, or BUN levels. Furthermore, Tt-SOD reduced inflammatory cytokine expression in prostate tissue and increased antioxidant capacity. This anti-inflammatory activity correlated with decreases in the abundance of cluster of differentiation 3 (CD3), cluster of differentiation 45 (CD45), and macrophage inflammatory protein 1α (MIP1α) cells. Tt-SOD alleviated inflammation and oxidative stress by reducing NF-κB P65 and P38 protein levels and increasing I-κBα protein levels. These findings support Tt-SOD as a potential drug for CP/CPPS.

Toxicometabolomics: Small Molecules to Answer Big Toxicological Questions

Given the high biological impact of classical and emerging toxicants, a sensitive and comprehensive assessment of the hazards and risks of these substances to organisms is urgently needed. In this sense, toxicometabolomics emerged as a new and growing field in life sciences, which use metabolomics to provide new sets of susceptibility, exposure, and/or effects biomarkers; and to characterize in detail the metabolic responses and altered biological pathways that various stressful stimuli cause in many organisms. The present review focuses on the analytical platforms and the typical workflow employed in toxicometabolomic studies, and gives an overview of recent exploratory research that applied metabolomics in various areas of toxicology.

Repeated Administration of Clinically Relevant Doses of the Prescription Opioids Tramadol and Tapentadol Causes Lung, Cardiac, and Brain Toxicity in Wistar Rats

Tramadol and tapentadol, two structurally related synthetic opioid analgesics, are widely prescribed due to the enhanced therapeutic profiles resulting from the synergistic combination between μ-opioid receptor (MOR) activation and monoamine reuptake inhibition. However, the number of adverse reactions has been growing along with their increasing use and misuse. The potential toxicological mechanisms for these drugs are not completely understood, especially for tapentadol, owing to its shorter market history. Therefore, in the present study, we aimed to comparatively assess the putative lung, cardiac, and brain cortex toxicological damage elicited by the repeated exposure to therapeutic doses of both prescription opioids. To this purpose, male Wistar rats were intraperitoneally injected with single daily doses of 10, 25, and 50 mg/kg tramadol or tapentadol, corresponding to a standard analgesic dose, an intermediate dose, and the maximum recommended daily dose, respectively, for 14 consecutive days. Such treatment was found to lead mainly to lipid peroxidation and inflammation in lung and brain cortex tissues, as shown through augmented thiobarbituric acid reactive substances (TBARS), as well as to increased serum inflammation biomarkers, such as C reactive protein (CRP) and tumor necrosis factor-α (TNF-α). Cardiomyocyte integrity was also shown to be affected, since both opioids incremented serum lactate dehydrogenase (LDH) and α-hydroxybutyrate dehydrogenase (α-HBDH) activities, while tapentadol was associated with increased serum creatine kinase muscle brain (CK-MB) isoform activity. In turn, the analysis of metabolic parameters in brain cortex tissue revealed increased lactate concentration upon exposure to both drugs, as well as augmented LDH and creatine kinase (CK) activities following tapentadol treatment. In addition, pneumo- and cardiotoxicity biomarkers were quantified at the gene level, while neurotoxicity biomarkers were quantified both at the gene and protein levels; changes in their expression correlate with the oxidative stress, inflammatory, metabolic, and histopathological changes that were detected. Hematoxylin and eosin (H & E) staining revealed several histopathological alterations, including alveolar collapse and destruction in lung sections, inflammatory infiltrates, altered cardiomyocytes and loss of striation in heart sections, degenerated neurons, and accumulation of glial and microglial cells in brain cortex sections. In turn, Masson's trichrome staining confirmed fibrous tissue deposition in cardiac tissue. Taken as a whole, these results show that the repeated administration of both prescription opioids extends the dose range for which toxicological injury is observed to lower therapeutic doses. They also reinforce previous assumptions that tramadol and tapentadol are not devoid of toxicological risk even at clinical doses.

Tramadol sensing in non-invasive biological fluids using a voltammetric electronic tongue and an electrochemical sensor based on biomimetic recognition

Tramadol (TRA) is a weak opioid analgesic, prescribed to relieve mild to moderately severe pain. However, side effects of TRA overdoses, including vomiting, depression, tachycardia, convulsions, morbidity and mortality are often reported. In this study, an electrochemical sensor based on molecularly imprinted conductive polymer was firstly developed for the quantitative and non-invasive detection of TRA. Secondly, a voltammetric electronic tongue (VE-Tongue) combined with chemometric methods was used for the qualitative analysis. The MIP sensor was constructed by self-assembling a poly-aniline layer coated with silver nanoparticles (PANI-AgNPs) on a screen-printed gold electrode (Au-SPE). Then, 2-amino-thiophenol was polymerised in the presence of TRA. The electronic device exhibits, under optimal conditions, responses proportional to TRA concentrations (0.01-100 µg/mL) with detection and quantification limits of 9.42 µg/mL and 28.55 µg/mL, respectively. Moreover, its selectivity was proven by insignificant interferences of substances (paracetamol and citric acid). Spiked saliva and urine samples were used for the sensor practical application with a significant recovery above 90% and standard deviations below 4.5%. Besides, urine samples' analyses using VE-Tongue and pattern recognition methods show good discrimination, classification, and prediction results with scores above 95%. Correspondingly, both electro-analytical devices could be viable for monitoring drugs in biological matrices.